The benefits of routine oil changes in a vehicle are well-known, Routine oil changes have been shown to increase engine life and performance. With repeated prolonged use, motor oil builds up suspended particles, metallic and non-metallic, from the abrasive and adhesive wear of engine parts against one another and from products of incomplete combustion and improper air intake. The particles in turn cause abrasive wear of the engine bearings, piston rings and other moving parts and the reduction of the motor oil lubricity as various additives and lubricating components become depleted. This adversely affects engine performance and if left unchanged can destroy or cripple the engine performance. It is recommended by at least one oil manufacturer that the level of total solid concentration be limited to levels below 3.0% with the levels of silica being present in amounts lower than 25 parts per million and sodium in amounts lower than 200 parts per million.
In currently designed vehicles, the oil pan serves the purpose of a reservoir for circulation of engine oil. Engine lubrication is generally accomplished through a gear-type pump. The pump picks up engine oil from the oil pan sump or oil is drawn up through the pick-up screen and tube, and is passed through the pump to the oil filter. The oil filter is generally a fullflow paper element unit. In some vehicles, an oil filter bypass is used to ensure adequate oil supply, should the filter become plugged or develop excessive pressure drop. Oil is routed from the filter to the main oil gallery. The gallery supplies valve train components with oil, and by means intersecting passages, supplies oil to the cam shaft bearings. Oil draining back from the rocker arms is directed, by cast dams in the crank case casting, to supply the cam shaft lobes. Oil also drains past specific hydraulic lifter flats to oil cam shaft lobes directly. The passages supplying oil to the cam shaft bearings also supply the crank shaft main bearings through intersecting passages. Oil from the crank shaft main bearings is supplied to the connecting rod bearings by means of intersecting passages in the crank shaft. The front cam bearing can include a slot on its outside to supply oil to the cam sprocket thrust face. In some engines, many internal engine parts have no direct oil feed and are supplied either by gravity or splash from other direct feed components. A bypass valve can also be disposed in the oil pick-up screen to ensure adequate oil flow if the screen should become restricted. A pressure regulator valve, sometimes located in the oil pump body, maintains adequate pressure for the lubrication system and bypasses any excess back to the suction side of the pump. Oil from the pump passes through the filter before going to the engine oil galleries. In the filter, the oil passes through a filtering element where dirt and foreign particles are removed.
To remove the contaminated oil, the drain plug, generally located in the lowermost region of the oil pan, is opened. The spent oil containing suspended particles is permitted to flow under gravity out of the pan into a suitable receptacle. After the spent oil is removed, the plug is replaced and fresh oil is added to the engine usually through a separate opening in the engine valve cover.
The oil change process is essentially the same whether performed at home, at service stations or at one of the various oil change centers which have opened in recent years. The flow rate, or time required for oil drainage, is almost the same for each of these locations because it is limited by the size of the drain plug aperture and the force of gravity.
Therefore, it would be desirable to provide a method which accelerates removal of spent oil conveniently, more completely, and easily from the crank case. It would also be desirable to provide a system which reduces the amount of spent oil handling as required in a conventional oil change service station. Finally, it is desirable to provide a method which would be easily employed by vehicle owners, especially those owning fleets such as truck fleet and car rental companies, with benefits of the method of the present invention such as time savings, money savings, convenience, minimum exposure to motor oil, environmental protection, energy conservation and finally, longer-lasting, better performing engines.